Foldable landing-gear for aeroplanes



F. MCCARROLL.

FULDABLE LANDING GEAR FOR AEHOPLANES.

APPLICATION 'FILED JULY I9. 1919. V A 1,I53,40"i. Patendsept. 21,1920,

3 SHEETS-SHEET I.

F. MCC'ARROLL. FOLDABLE LANDING GEAR FOR AEROPLANES.

APPLICATION FILLD, 1U I.. Y 19.1919.

Patented Sept. 21, 1920.

3 SHEETS-SHEET 2.

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Juventa Ffa/7i /V-CZZ/"ro @nomini F. MCCARRULI.. FOLDABLE LANDING GEAR FOR AEROPLANES.

APPLICATION FILED IULY I9, I9I9 k. En

. UNITED STATI-:s

APlxv'rslvlr orrlclg.

FRANKMocARnoLi., yoF DALLAS, TEXAS.

i FOLDABLE LANDING-GEABaFOR AROPLANES.

Specification of Letters fate-111:. Patented Sept. 21, 1.920.

Application filed July 19, 1919. Serial No. 311,948.-

To all whom t may concern:

Be it known that LFRANK MoCARRoLL,

`a citizen of the United States, residing at Dallas, in the county of lDallas and State of Texas,` have invented certain new and useful Improvements in Foldable Landing- Gears for Aeroplanes, of which the following is a specification.

This invention relates'to aeroplanes and landing gear therefor. yMore specially the invention relates to a fouldable type landing gear for-aeroplanes andv other aircraft.

' An object of the invention is to provide the design of `an aeroplane 'landing gear which .will fold into upwardly disposed position and lay adjacent the fuselage or body of said plane.

AAnother purpose is toprovide a foldable landing gear capable of being v folded and unfolded from the aviatorsseat in order that the aviator may lift the landing gear up wardly along Side the fuselage after the plane has taken to the air and adapted to be unfolded into aV landing position as the machine descends to alight.

A further object of the invention is. to employ shock absorbers or resilient members in-connection with the landing gear or under-carriage which will impart a steady and yieldable supporting tendency to the body of the plane as the plane alights. It is also a feature to provide streamline linclosure pockets into which .the Wheels of4 the landing gear will register when said Wheels are moved linto upwardly folded position.

With the above principal objects, and others, in view, the invention has relation to a l certain combination and arrangement of aeroplane landing gear parts, an example lof which is portrayed in the following description, delineated in the appended claims, and illustrated in the accompanying drawings, wherein: p

-Figure 1. shows-a. side elevation of the l foldable landing gear structureV disposedl in4 alighting position, and shown in dotted lines to be in upwardly folded position.- Fig. 2 shows a front view of the. foldable landing gear detached from the fuselage..

or aeroplane body.

. Fig. r3 shows a plan viewil-of the landing" gear removed from the aeroplane body.

Figl- 4showssi'de elevation 'of the land'- ing gear mounted upon a fragmentary view of pqan. aeroplane, said landing gear being moved in anupWa-rdly folded position with the plane represented in flight.

Fig. 5 illustrates a sectional detailed view A landing gear constructed according to y l the present specifications and claimsy of this disclosurecomprises a telescoping axle tted with the usual ground wheels. longerontubes are employed for mounting the device on the fuselage body of an aeroplane, and a pair of foldable braces with a A pair of.

pair of landing gear struts are associated 1 with the longeron tubes. A lever is corre# lated with the device and adapted to move thebraces and landinggear struts into an upwardly folded position..

Referring now' more 1n particular to the l drawings, the reference numeral 10 designates apair of spaced lon eron tubes'. Each longeron tube is fitted Wit several longeron clamps 11. These clamps are fixed to the y tubes and provided with a square receptacle l through whichv may be inserted the longerons or main beams 12 of 'an aeroplane. Themembers 12 constitute the main frame of an. aeroplane body, and it is to these members 1 2 that the device .is attached;

,The clamps are provided with suitable bolts v13 'which allows the clamps to be opened or loosened on theI side to permit the insertion of the longerons 12. Spacer tubes 14 are integrally made with or welded to the longeronv clamps I1 1 and lact to space the" longeron tubes apart in fixed relation. The

tubes '14 thus `brace the struct-ure and add to the strength. of: the fuselage of thevaeioplane.;

vk"Qn, the forward end'of, each longeron tubeis pivotally confined a cuil' 15 'provided with a` pair of integral out-spaced ears 16. The

culsvl-arejournaled upon the end ofthe longerontubes'. l A landing gear strut is absorbing system is undergoing action. A l

ivotally mounted in the ears 16 of each cuff. ach landing gear strut comprises a pair of telescope members 17 and V18, -with`the upper end thereof secured between the ears by a pin which permits the telescoping strut to pivot von the cuff. A shock absorbing spring 19 is confined between the web 20 and a fixed piston 21. secured to the upper telescoping member 17 while the lowerend of the-spring is seated against the web 20 `integrally lformed in the tube 18. `This provides a resilient support for the tube 17 upon tube 18, and in this manner the weight of the aeroplane lis transmitted through the spring 19 tothe lower member 18. It may be desirable to employ rubber shock absorbing means and in suc case the rod 22 which carries the piston 21 will berfitted with a pin 23, and the tube 18 will be provided with pins 24. The two sets of pins 23 and 24. are adapted to move relatively one with the other when the shock shock absorbing plug 25. is placed in the tube 18 with the pin sets 24 and 23 imbedded therein. The shock absorbing plug will undergo compression and tension during the telescoping action of the landing gear strut. The above described shock absorbing means is provided in each landing gear strut.

The lower end of the strut section 18 is pivotally confined between ears V26, said ears integrally formed with a cuff 27; An axle member is carried .on the lower end of each landing gear strut and mounted in the two cuffs 27. The axle comprises telescoping members 28 and 29. The axle part 28 telescopically. receives the member 29. The axle part 29' is fitted on the end thereof with a shoulder head 30, said shoulder head is 'confined in the tube 28. The tube 28 is provided with a shoulder 31 abutting the shoulder head 30. vThe two`shoulders act to form a solid axle member and prevent spreading of the landing gear when the aeropane alights. The axle parts 28 and `29 will telescope one on the other when the landing gear is folded up, as later seen.

A brace 32 is employed on each side of the landing gear with the upper end thereof pivoted to ears 33 integrall formed on a cuff 34. The cuff 34 is slldably confined upon the longeron tube 10. The lower end of the brace 32 is rotatably mounted in theA cuff 35, and the forward end of this brace 32 is turned up at 36 to form a skid to prevent the landlng gear parts from digging into the ground in case the aeroplane lands on soft vsoil or in case the wheels collapse.

The culf 35v is pivotally mounted on a stud 37, said stud Abeing fixed to the sleeve 27. This Apermits the cuff 35 to rotate upon the 4stud during the upward folding movement and during the telescoping action of the axle The piston 21 is` `tubes 10. This action on t parts 28 and 29. The above described brace Y each side of the levers 41 with the cuffs 34. The links 42 areconnected to the cuffs 34 b an eye and to the levers 41 with a pin. inks 43 join the cuffs 15 with the arms 40. A hand lever 44 is fixed to the tube 39 and employed to rotate said tube upon the spacer member 38.

ThusI when the hand lever 44 is moved rearwardly the levers 41 travel downwardly and exert a pull on the cuffs 34 which slides sai-d culi's 34 forward alon the longeron e part of the lever moves the landing gear struts forward and about the pivotal int in the ears 16. Simultaneously with thls action the links 43 draw the cuffs 15 rearwardly which moves the upper ends of the landing gear struts rearwardly along the tubes 10 untll all parts assume the position shown in dotted lines in rThe hand lever 44 is provided with a pawl and ratchet mechanism comprising the ratchet bolt-45 guided through a' hole formed in the tube 39. A toothed rack 46 is formed on the spacer member 38 and enga cable by the ratchet 45 of the hand lever. hus the 'hand lever is locked in fixed position when.

the landingv gear is pivoted in upwardly or downwardly displacedl position.

Should it be necessar to employ additional bracing means ot er than the brace members 32, there is shown a pair of diagonal rods or wires 47. The lower ends of the diagonal braces 47 are attached to an eye formed in each of the ears 26, while the upper ends of saidfbraces are secured to eyes integrally formedon the central longeron clamps 11. The eye connections on the diagonal braces permit freedom of movement between the braces and joined parts so that no interference or restriction of movement occurs when the landing' gear is moved into folded iight position. In Fig'. 4 there is shown a stream line pocket 48 built on the side of the fuselage 49 of the aeroplane.l These wheel pockets 48 are employed to partl receive the Wheels when the gear is folde in upward position. This reduces head resistance of the wheels passing through the air.

It may be desirableto design thisI foldabl 27, said view'eeing il us-` landing gear so it will fold into the body of the machine. In such case it will only be necessary to form receptacles in the lower portion of the fuselage into which the wheels wilh move when folded up. In order to'have as blload gage tread as possible the present drawings show the wheels folded into'stream Vline position and into the stream line pockets formed on the outside' of the fuselage.

The aviator can readily control the operation of the foldable landing gear from the hand lever 44:. After the aviator drives his plane into the air he will pull the lever y4:4: rearwardly which action moves the -duces the head resistance of the 4plane in flight.

An aeroplane equipped with this type of foldable landing vgear will have a greater radius ofv flight since its miles per hour is increased. This type of foldable landing gear is especially designed for use in connection with aeroplanes having square .fuselage bodies.

Where an aeroplane is designed and con,-

structed with the intention of installing,

this type of gear, the longeron may be made round and inserted within the longeron `tube and thereby eliminate the use 'of the longeron clamps 11. But wherethe 'aeroplane has already been built and it becomes V. desirable to equip said plane with this foldable type of landing gear, it will .be only necessary to remove the old landing gear and substitute the -foldable gear here described by installing same uponl the lower longeron members 12 .of the aeroplane fuselage. In this manner the foldable landing gear may be installed on an aeroplane in a very short time by attaching the several clamps l1 shown. The present drawings disclose six longeron clamps 11, and it is thought that this is suilicent to provide a substantially strong and stiff assembly when v the landing gear has been anchored to the fuselage body. A special feature of the present landing gear resides in the ability of the aeroplane mechanics to very carefully adjust the center ofv ground running balance of the plane. vShould the wheels of the running gear be placed a little too far4 forward or to the rear ;of the preferred point of mounting, the longeron clamps 11 posed position.

will be loosened and the complete landing gear, as a unit, moved'rearwardly or forwardly to correct the ground running balance of the plane. The present design of landing gear is built as a unit and can be installed and removed in a very short time by one or two mechanics. Y

In my application for'patent filed 19 day of October, A. D. 1918, under the Serial No.

258,867, I have shown another form of foldable landing gear which has special characteristics adapting it for use in connection with the V type or angular shape fuselage. This last indicated invention will, therefore, be employed on V-shaped fuselages or aeroplanes, while the present disclosure provides the preferred form of foldable landing gear for use on present day rectangular-shaped fuselage or aeroplane body.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent is:

l 1. A foldable landing gear comprising; 'a

pair of spaced longeron tubes attachable to and detachable from the longerons of an aeroplane fuselage, a landing gear. strut pivoted on each longeron tube, an axle car-j ried by the landing gear struts, and braces associated with each longeron tube and each landing gear strut. A

2. A foldable landing gear comprising;

apair of spaced longeron tubes attachable to and detachablefrom the longerons of an aeroplane fuselage, apivoted landing gear strut carried on each longeron tube, an axle carried by the'landing gear struts, braces associated with each longeron tube and each landing gear strut, and means for foldingy the aforesaid part.c into an upwardly dis- A- foldable landing gearV attachment for air craft comprising; a pairuof longeron tubes, clamps fixed thereto, to fasten the attachment' to'` the fuselage -of aircraft,

Acuiis slidably mounted on the tubes, 'land` in gear struts -pivotally carried on the cu s, a telescoping axle carried by the landing gear struts and braces 4employed between thelanding gear struts andv longeron tubes. l -y 4. A foldable landing gear attachment for aircraft comprising; a pair of longeron tubes,` clamps fixed thereto, to fasten the attachment to the fuselage of aircraft, cuffs slidably mounted on the tubes, landing gear struts pivotally carried on the cuffs, a telescoping axle carried by thelanding gear struts, braces employed between the landing gear struts and longeron tubes, and shock absorbing means arranged in each landing gear strut.l

5. A foldable pair .of longeron tubes, clamps fixed thereto, cuffs slidably mounted thereon, landing gear struts pivotally carried on the cuis, a

landing gear comprising; a

telescoping-axle carried by the landing gear struts and braces employed between the landing gear' strutsl and longeron tubes,

shock absorbing means fitted in each landing' gear strut, and means for folding the labove aforesaid landing gear into upward position to reduce head resistance.`

6. A foldable landing gear comprising; a

' pair of spaced longeron tubes,'provided with a front and rear set of sliding cuffs, a hand lever, a pair of'V links attached to the hand Nlever and connecting with each set of cuffs, a4 landing gear strut carried by the front cuffs,

a wheel axle carried by the landing gear struts, and a pair of braces associated with the landing gear` struts and the longeron tubes to brace the landing gear.

7. A foldable landing gear comprising; a pair of spaced longeron tubes, apair ofy braces with the upper ends thereof slidablyv associated with -the longeron tubes, a pair of landing gear struts pivotallyl mounted upon the forward end of the longeron tubes, with meansforpivotally joining the braces to the lower portion of the landing gear struts, vand means provided for foldingthe landing gear in upward position.

8. A foldable landing gear comprising, avl pair of spaced longeron tubes, clamps for joining the `longeron tubes to the fuselage ofa standard model aeroplane, a landing gear strutpivoted on each longeron tube. andy depending therefrom, a wheel carried on each strut, and a brace connecting each landing gear strut with each longeron tube.

9. A foldable landing gear comprising, a

pair of spaced longeron tubes, clamps for 1o' the longeron tubes to the fuselage of la stan ardmo el aeroplane, a landing gear strut pivoted on each longeron tube and de-y pending therefrom, a wheel carried on each strut, a brace connectingJ each landing gear strut with each longeron tube, and a collapsible axle joining the lower end of each landin gear strut.

' 10. foldable landing gear comprising, a pair of spaced longeron tubes, clamps for )oinin the lon eron tubes tothe fuselage of a. stan ard m el aeroplane, a landing gear ,ing` gear being" capable of folding u strut: pivoted` on each longeron tube and depending therefrom, a. wheel. carried on each strut,y a brace connecting each landing: gear strut with eachy longeron tube, a collapsible axle joining the. lower end of each landing gear' strut tube rotatably confined between the longeron tubes, a lever secured to thetube, connecting' means interposed between the tubeI and the landin ear struts for movingl the struts when t e ever is moved, and connecting* means interposed between the tube andthe braces for moving the said braces when thelever is moved to execute an upwardly folding action of the wheels and braces.

1l. A landing gear for aircraft, said land- 1n streamline-position with uthe fuselage o the cra-ft, and characterized as new by employing a telescoping axle as a part of the landing gear, a` lever placed. in suitable position struts, landingwheels mounted on the axle,

braces arranged' between thev longerons and axle to maintain the landing gear in properly extended alighting position, and controlv means provided to simultaneously fold the axley upwardly telescoping its parts,

whereby the landing gear assumes azstreamline position adjacent the fuselage.

In` testimony whereof I affix my signature.

FRANK MCCARROLL. itnesses R. H. VOGEL, CHAs. R. RUSSELL. 

